1. Field of the Invention
This invention relates to an electromagnetic protection and control assembly enabling mechanical attachment and electrical connection of several electrical switch devices, particularly for making an assembly comprising a combination of at least two electrical devices such as a contactor, a circuit breaker, an isolating switch, a fused isolating switch, a thermal relay or any other similar electrical device that can be used for low voltage electrical distribution or control. The invention also relates to an electrical device that could be used in the composition of such a protection and control assembly.
2. Discussion of the Background
In an assembly intended for the protection and control of an electrical motor (usually called a “motor start assembly”) or any other low voltage multipole electrical load, a first electrical protection device such as a circuit breaker or a fused isolating switch is frequently used in cascade with a second electrical control device such as a contactor, these two devices being connected to each other. Other devices such as a thermal protection relay can also be added to this combination.
It is desirable to be able to make such a motor start assembly as easily and quickly as possible, while maintaining a dependable connection. For obvious reasons of cost and time saving during assembly/wiring and space saving in electrical boxes or cabinets in which the assembly is installed, an attempt is made particularly to eliminate any conductors (wires, bars) forming connections between the devices to minimise the number of electrical connections to be made and to minimise the total size of the different associated devices.
Solutions are already available, particularly in document EP0588712, in which a specific part is fitted between the two electrical devices and that integrates rigid conductors so that connections can be made to the corresponding terminal blocks on the two electrical devices, in order to make mechanical and electrical connections more quickly. However, this solution requires a connection operation on the terminal blocks of the two devices and it may also be necessary to separate the two devices from each other in order to insert this part.
Document WO0046880 describes a system in which the electrical devices comprise terminal blocks provided with elastic terminals in which an interconnection block is inserted between the two devices directly from the front. The system also comprises complementary mechanical attachment means on the two devices in order to complete their mechanical attachment. However, this solution is not suitable for screw terminals frequently used particularly in devices used to switch a high power electrical current, for example equal to or more than 32A at 400V. Furthermore, the interconnection block requires the presence of a specific terminal block on each unit.